<template>
  <div class="com-container">   
    <div class="com-chart" ref="hot_ref">     
    </div>
    <span :style="comStyle" @click="toLeft" class="iconfont arr-left">&#xe6ef;</span>
    <span :style="comStyle" @click="toRight" class="iconfont arr-right">&#xe6ed;</span>
    <span :style="comStyle" class="cat-name">{{catName}}</span>
  </div>
</template>

<script>
import {mapState} from 'vuex'
import { getThemeValue } from '@/utils/theme_utils'
export default {
  data () {
    return {
      chartInstance: null,
      allData: null, // 从服务器获取的所有数据
      currentIndex: 0, // 当前所展示的一级分类数据
      titleFontSize: 0
    }
  },
  computed: {
    catName() {  // 右下角一级分类名称的展示
      if(!this.allData) {
        return ''
      } else {
        return this.allData[this.currentIndex].name
      }
    },
    comStyle() { // 控制箭头以及标题样式
      return {
        fontSize: this.titleFontSize + 'px',
        color: getThemeValue(this.theme).titleColor
      }
    },
    ...mapState(['theme']) 
  },
  watch:{
    theme() {
      console.log("主题切换了");
      this.chartInstance.dispose() // 销毁当前的图表
      this.initChart() // 重新以最新的主题名称初始化图表对象
      this.screenAdapter() // 完成屏幕适配
      this.updateChart() // 更新图表的展示
    }
  },
  created() {
    // 在组件创建完毕后, 注册回调函数
    this.$socket.registerCallBack("hotData", this.getData)
  },
  mounted() {
    this.initChart()
    // this.getData()
      this.$socket.send({
      action: 'getData',
      socketType: 'hotData',
      charName: 'hotproduct',
      value: ''
    })
    window.addEventListener("resize", this.screenAdapter)
    this.screenAdapter()
  },
  destroyed() {
    window.removeEventListener("resize", this.screenAdapter)
    // 再组件销毁的时候,进行回调函数的取消
    this.$socket.unRegisterCallBack("hotData")
  },
  methods: {
    // 初始化方法
    initChart() {
      this.chartInstance = this.$echarts.init(this.$refs.hot_ref, this.theme)
      const initOption = {
        title: {
          text: '▎热销商品销售金额占比统计',
          left: 20,
          top: 20
        },
        legend: {
          top: '15%',
          icon: 'circle'
        },
        tooltip: {
          show: true,
          formatter: (arg) => {
            // console.log(arg);
            const thirdCategory = arg.data.children
            // 计算出所有三级分类的数组总和
            let total = 0
            thirdCategory.forEach(item => {
              total += item.value 
            })
            // 计算每个三级分类的占比情况
            let retStr = ""
            //  三级分类的名称:三级分类的百分比
            thirdCategory.forEach(item => {
              retStr += `
              ${item.name}:${parseInt(item.value / total * 100) + '%'}
              <br />
              `
            })
            return retStr
          }
        },
        series: [
          {
            type: 'pie',
            label: {
              show: false
            },
            emphasis: {
              label: {
                show: true
              },
              labelLine: {
                show: false
              }
            }
          }
        ]
      }
      this.chartInstance.setOption(initOption)
    },
    // 获取服务器数据方法
     getData(ret) {
      // await this.$http.get()
      // 对allData进行赋值
      // const {data:ret} = await this.$http.get('hotproduct')
      this.allData = ret
      console.log(this.allData);
      this.updateChart()
    },
    // 更新图表
    updateChart() {
      // 处理数据
      const legendData = this.allData[this.currentIndex].children.map(item => item.name)
      const seriesData = this.allData[this.currentIndex].children.map(item => {
        return {
          name: item.name,
          value: item.value,
          children: item.children
        }
      })
      const dataOption = {
        legend: {
          data: legendData
        },
        series: [
          {
            data: seriesData
          }
        ]
      }
      this.chartInstance.setOption(dataOption)
    },
    screenAdapter() {
      this.titleFontSize = this.$refs.hot_ref.offsetWidth / 100 * 3.6
      const adapterOption = {
        title: {
          textStyle: {
            fontSize: this.titleFontSize
          }
        },
        legend: {
          itemWidth: this.titleFontSize * 1.3,
          itemHeight: this.titleFontSize * 1.3,
          itemGap: this.titleFontSize /2,
          textStyle:{
            fontSize: this.titleFontSize /2
          }
        },
        series: [
          {
            radius: this.titleFontSize * 5,
            center: ['50%', '60%']
          }
        ]
      }
      this.chartInstance.setOption(adapterOption)
      this.chartInstance.resize()
    },
    toLeft() {
      this.currentIndex--;
      if(this.currentIndex < 0) {
        this.currentIndex = this.allData.length - 1
      }
      this.updateChart()
    },
    toRight() {
      this.currentIndex++;
      if(this.currentIndex > this.allData.length - 1) {
        this.currentIndex = 0
      }
      this.updateChart()
    }
  },
}
</script>
 
<style lang = "less" scoped>
  .arr-left{
    position: absolute;
    left: 10%;
    top: 50%;
    transform: translateY(-50%);
    cursor: pointer;
    color: #fff;
  }
  .arr-right{
    position: absolute;
    right: 10%;
    top: 50%;
    transform: translateY(-50%);
    cursor: pointer;
    color: #fff;
  }
  .cat-name {
    position: absolute;
    left: 80%;
    bottom: 20px;
    color: #fff;
  }
</style>